This invention relates to improvements in apparatus and methods for performing a variety of soil subsurface conditioning treatments and related activities including but not limited to trenching and cable laying. In our U.S. Pat. No. 5,756,966, the disclosures of which are incorporated herein by reference, there is described an improved sub-surface trenching and backfill apparatus. The apparatus disclosed therein comprises, inter alia, a self-propelled prime mover to which various implements may be connected including, but not limited to, a soil sub-surface trenching apparatus for subsurface delivery of a ribbon deposit of aggregate material. The prime mover is adapted to supportably mount an aggregate feed hopper and a centerless auger assembly of the apparatus. The prime mover is further equipped with a vibratory drive attachment that is adapted to connectably support and operationally position the vibratory trenching blade and trenching blade-trailing aggregate feed chute of the apparatus.
In a typical operation the self-propelled prime mover with the vibratory drive attachment held in a transport position by extension of the vibratory drive attachment lift cylinder is moved to and located for operational soil insert of the vibratory trenching blade with trenching blade-trailing aggregate feed chute. The hydraulic vibrator motor is activated to impart a variable high frequency impulse within a range of from 0 up to 2,400 cycles per minute and higher to the trenching blade while at the same time retracting the lift cylinder and imparting forward driven displacement to the prime mover, all which effects mechanical soil insertion of the blade and trench vane to the set operational depth for trench forming and backfilling. Upon activation of the centerless auger assembly there is effected conveyancing of aggregate material from the feed hopper to the feed chute for trench vane dispensing of aggregate material in backfilling of the trench and progressive formation of the soil sub-surface aggregate filled surface water drainage channel.
The apparatus of our prior patent has achieved considerable success in operation and has relieved many properties of excess moisture without the expense and difficulty of prior art French drains and related methods. In addition, the apparatus of our prior patent has been useful in creating root barriers for trees and other uses. Many golf courses, parks and other areas have a need for a soil sub-surface trenching apparatus for subsurface delivery of a ribbon deposit of aggregate material. However, many of these locations have limited budgets for the purchase of equipment. To have a specialized motive source for pulling the trenching apparatus is not practical. However, most of these locations have one or more tractors present to attend to their various landscaping needs. These tractors are a prime source for the motive power to pull the trenching apparatus of our earlier invention.
When the prime mover is in the form of a conventional tractor, however, difficulties have been encountered in performing the aforementioned vibratory trenching. Conventional tractors employ three-point hitches that correspond to connections on a variety of farm and landscaping attachments. In attaching implements to a conventional tractor having the three-point hitches requires a significant degree of effort. Not infrequently, there is a fair amount of back and forth movement of the tractor to achieve the necessary precise alignment of the lower connections on the hydraulic lift arms with the corresponding connections on the implement. The upper connection is similarly difficult to make. One of the major problems that have been encountered in using conventional tractors with a vibratory trenching apparatus is the problem of lateral sway and vertical movement. The hydraulic lift arms on a conventional tractor can but usually do not provide sufficient downward pressure on an attachment to keep it in place on the ground and most rely upon their inherent weight and/or suction to keep the implement in the ground. However, there is usually considerable lateral sway in the hydraulic lift arms on alignment when an attachment is to be connected to a conventional tractor. While some of this sway is counteracted by the presence of lateral stabilizer bars, there is still considerable sway in the attachment. While the presence of sway is not necessarily a significant problem in most tractor applications such as plowing, cultivating etc., it presents a significant problem when a vibratory drive attachment is being used with the tractor three-point hitches. Because of strong vibrations of the vibratory drive member when it encounters various soil conditions (impervious, compacted, etc.), the swaying of the lift arms and upper connection cause the vibratory drive member to meander from the line of travel as well as causing the vibratory drive member to become lifted from below the surface of the soil. This causes gaps in the trench and reduces the drainage or other desired properties of the trench thus decreasing the effectiveness of the treatment. Similar problems with lateral sway are also encountered in the use of other devices, such as for example a stump grinder where the side to side movement permitted by the conventional three-point hitches on tractors causes the stump grinder to move off the desired grinding location during operation.
There are prior art devices using vibratory mechanisms with a three-point hitch on conventional tractors. In Re U.S. Pat. No. 34,289 to McCain, there is disclosed an angularly adjustable vibratory trench filling attachment assembled by means of a three-point hitch to the side of a tracked vehicle. There is no teaching in McCain of a vibratory drive member that inserts a blade into the soil to form a trench or any of the issues relating to swaying. McCain in fact is primarily a sifter to sift dirt without rocks and stones into a trench and as a result, swaying is not an issue in this patent. In U.S. Pat. No. 4,625,989 to Allen there is disclosed a tractor/implement hitch that provides a draw bar pickup type hitch which is used in conjunction with a conventional three-point hitch.
There are a number of prior art hitches for tractors that are known in the art. For example, U.S. Pat. No. 4,069,885 discloses a hitch having three-point attachment of an inverted V shaped frame for lifting by a tractor into a recess of an inverted V shape in a connecting device carried by an implement. No provision for use with a vibratory drive attachment is disclosed. U.S. Pat. No. 4,509,768 discloses a tractor hitch utilizing a horizontal transverse pin carried between cheek plates which gradually straddle a downwardly tapering triangular leg depending from a horizontal leg which extends outwardly from the top of a vertical mounting plate on an implement. After upward movement of the pin and cheek plates, the base of the triangular leg, which is slightly shorter than the distance between the cheek plates, is confined between the cheek plates and beneath the hook formed by the downwardly extending triangular leg and is approximately centered with respect to the axes of the vehicle. There is also no disclosure of vibratory drive attachment or the problems associated with such devices.
The prior art is further exemplified by U.S. Pat. Nos. 4,015,85 and 4,431,207 both of which illustrate apparatus for securing agricultural implements to tractors utilizing three-point hitches. The object of both patents is to provide apparatus for engaging and disengaging an implement or tow vehicle wherein the operator does not have to leave the tractor. The apparatus of both of these patents relies upon engagement of a tongue of the implement between members presenting aligned holes for receiving a vertical hitch pin actuated by a fluid operated cylinder. The alignment problems presented by these patented apparatus appear to be nearly as great as those presented by conventional hitches. The prior art is further illustrated by U.S. Pat. Nos. 4,867,607, 5,084,991, 5,190,409, 5,224,797, 5,975,804, 2,635,890, 2,822,739, 2,983,523, 3,716,253, 3,956,331, 3,889,979 and 3,951,435.
The principal object of the present invention is to provide a stationary platform to mount various surface and subsurface apparatus including but not limited to trenching, vibratory plowing and a soil sub-surface trenching apparatus for subsurface delivery of a ribbon deposit of aggregate material that may be used in conjunction with a conventional tractor having a three-point hitch.
It is another object of the present invention to provide a hitch that eliminates swaying on a conventional tractor having a three-piece hitch so that there is a stable platform to mount various surface and subsurface apparatus including but not limited to trenching, vibratory plowing, and a soil sub-surface trenching apparatus for subsurface delivery of a ribbon deposit of aggregate material which may be propelled by a conventional tractor.
It is also an object of the present invention to provide a hitch for connecting apparatus such as a trencher, a stump grinder and other devices to a conventional tractor where lateral sway of the apparatus is minimized during operation.
The present invention is directed to an apparatus for connecting a device or implement to a tractor wherein the tractor is equipped with a conventional three-point hitch. The apparatus includes a frame having a top member and a bottom member, which are joined together by a pair of side members. Each side member is adapted to be pivotably connected to a hydraulic lift arm of a tractor and the top member is adapted to be pivotably connected to a top arm of a tractor. Each of said side members further adapted to be pivotably connected to a stabilizer bar. The stabilizer bar is adapted to be pivotably connected to said tractor. The stabilizer bars prevent lateral movement and upward movement of the frame when the frame is connected to a tractor.